Crossbow-style benders are used to bend tubing or piping for a variety of applications. Crossbow benders are helpful in achieving the desired bend angle with accuracy. However, the inventors have discerned a number of disadvantages of previously known crossbow benders.
One disadvantage is that such benders are difficult to set-up and operate. To accommodate different tubing or piping sizes, shapes and bend radii, the forming bar, which acts against the side of the tubing opposite the mandrel, must be changed or adjusted for the particular tubing to be bent. Typically, hand-operated benders utilize two or more forming bars. For example, one forming bar may be utilized for ¼″-⅜″ tubing, and another forming bar for ½″-⅞″. The forming bar is typically attached to the bender by a screw or bolt. To change out forming bars, the user must remove the screw or bolt to remove the attached forming bar, and then screw or bolt on the other forming bar.
This procedure to switch out forming bars can be time-consuming and cumbersome. In addition, as only one of the forming bars is attached to the bender, the other forming bar(s) may become lost or difficult to find in a toolbox, which may be full of different tools. Further, it may be unclear or not easy to identify which forming bar is to be utilized with particular tubing.
A bender sold by Rothenberger USA of Rockford, Ill. addresses the use of multiple forming bars. The Rothenberger device utilizes one forming bar for a range of tubing sizes. However, the forming mandrels on the forming bar must be removed from the bar and repositioned to different locations on the bar for different tubing sizes. Thus, the Rothenberger device still requires time-consuming and cumbersome rearrangement of the mechanism.
Another problem identified in previous crossbow benders is that, after bending, the tube can be difficult to remove from the bending mandrel. This occurs, at least in part, due to cross-sectional deformation of the tubing during bending. Not only does removing a tube that is “stuck” in the bending mandrel take time and effort, but the force required to remove or unstick the bent tube can damage or distort the tube, or alter the bend or shape of the tube, which is undesirable. This is particularly so if tools are required, e.g., a hammer or pliers, to remove the tube.